1. Field of the Invention
The present invention illustrates a data center network flow migration method and system, and more particularly, a data center network flow migration method and system with low computational complexity.
2. Description of the Prior Art
With the advancement of cloud computing system, virtualization technique becomes an important issue in our daily life. The idea of virtualization technique is to use several virtual machines instead of a physical host server. These virtual machines are operated in parallel and can provide reliable service quality. However, when the virtualization technique is applied to cloud computing system, the data center network requires massive computational complexity, computational capability, and data storage capacity. Thus, a soft defined network (SDN) system in conjunction with Openflow structure is developed by Stanford University. The original propose is to extend the programmable capability for campus network and provide the corresponding virtualization client interface. Generally, the soft defined network includes a centralized controller and thousands of switches. These switches are interconnected and coupled to all physical host servers through complex link paths. Specifically, these interconnected switches are assigned according to a topology structure. In other words, the data center network under soft defined network is established according to the topology structure.
However, data center network includes massive number of switches. A pair of physical servers can communicate through a link path located on several switches. When data center network suffers heavy traffic load that at least one link path is over-utilized, traffic congestion may be occurred in high probability. To avoid traffic congestion, all switches and link paths in data center network have to be dynamically allocated at any moment. By doing so, the utilized load of link path can be reduced. Thus, the traffic congestion in data center network can be mitigated. To achieve dynamic allocation, dynamic and disjoint edge node divided spanning tree (D2ENDIST) algorithm can be applied in data center network. The D2ENDIST algorithm performs dynamic allocation by calculating the number of nodes, the combinations of traffic load in each node, and all possible rerouted link paths. Thus, when D2ENDIST algorithm is applied to data center network for optimizing the allocation of all switches and link paths, the computational complexity is extremely high (i.e., 5th powers increasing rate) so that the hardware for D2ENDIST algorithm is difficult to realize.
Thus, it is important to develop a flow migration method for optimizing the allocation of all switches and link paths with low computational complexity in data center network.